<div>
  <svg xmlns="http://www.w3.org/2000/svg" width="5cm" height="5cm">
    <desc>Two groups, each of two rectangles</desc>
    <g id="group1" fill="red" data-test="test">
      <rect x="1cm" y="1cm" width="1cm" height="1cm" data-foo="12"/>
      <rect x="3cm" y="1cm" width="1cm" height="1cm"/>
    </g>
    <rect x=".01cm" y=".01cm" width="4.98cm" height="4.98cm"
          fill="none" stroke="blue" stroke-width=".02cm"
          <warning descr="Attribute dta-foo is not allowed here">dta-foo</warning>/>
  </svg>
</div>
